package org.inspursc.s0517.health.common.security;

import org.apache.commons.lang3.StringUtils;
import org.springframework.security.access.AccessDecisionManager;
import org.springframework.security.access.AccessDeniedException;
import org.springframework.security.access.ConfigAttribute;
import org.springframework.security.authentication.InsufficientAuthenticationException;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.stereotype.Service;

import java.util.Collection;
import java.util.Iterator;

@Service
public class MyAccessDecisionManager implements AccessDecisionManager {

    // decide 方法是判定是否拥有权限的决策方法，
    //authentication 是释CustomUserService中循环添加到 GrantedAuthority 对象中的权限信息集合.
    //object 包含客户端发起的请求的requset信息，可转换为 HttpServletRequest request = ((FilterInvocation) object).getHttpRequest();
    //configAttributes 为MyInvocationSecurityMetadataSource的getAttributes(Object object)这个方法返回的结果，此方法是为了判定用户请求的url 是否在权限表中，如果在权限表中，则返回给 decide 方法，用来判定用户是否有此权限。如果不在权限表中则放行。
    @Override
    public void decide(Authentication authentication, Object object, Collection<ConfigAttribute> configAttributes) throws AccessDeniedException, InsufficientAuthenticationException {

        boolean isAccess = false;
        if (configAttributes == null) {
            throw new AccessDeniedException(" 没有权限访问");
        }
        //所请求的资源拥有的权限(一个资源对多个权限)
        Iterator<ConfigAttribute> iterator = configAttributes.iterator();
        while (iterator.hasNext()) {
            ConfigAttribute configAttribute = iterator.next();
            //访问所请求资源所需要的权限
            String needPermission = configAttribute.getAttribute();
            if (StringUtils.isNotEmpty(needPermission)) {
                //用户所拥有的权限authentication
                for (GrantedAuthority ga : authentication.getAuthorities()) {
                    if (needPermission.equals(ga.getAuthority())) {
                        return;
                    } else {
                        isAccess = false;
                    }
                }

            } else {
                String s = configAttribute.toString();
                if ("permitAll".equals(s)) {
                    isAccess = true;
                    break;
                }
            }
        }
        /*if (isAccess) {
            return;
        } else {
            throw new AccessDeniedException(" 没有权限访问");
        }*/
        throw new AccessDeniedException(" 没有权限访问");
    }

    @Override
    public boolean supports(ConfigAttribute attribute) {
        return true;
    }

    @Override
    public boolean supports(Class<?> clazz) {
        return true;
    }
}
